Human Pancreatic Duct Cells Exert Tissue Factor-Dependent Procoagulant Activity

Abstract

Activation of the coagulation cascade contributes to early graft loss and intraportal thrombotic events in clinical islet transplantation. Although these complications were shown to be related to the presence of tissue factor in human islet preparations, the contribution of duct cells, which represent a major contaminant of clinical islet isolates, has not been specified so far. Herein, we used flow cytometry, immunohistochemistry, RT-PCR, and functional coagulation assays to demonstrate that duct cells exert a potent factor VII-dependent procoagulant activity related to their expression of tissue factor. Both the classical membrane-bound and the recently described soluble form of tissue factor were shown to be synthesized by duct cells. We conclude that contaminating duct cells contribute to early ␤-cell damage after islet transplantation through their involvement in tissue factor-mediated thrombotic and inflammatory events.

N-Acetylcysteine derivative inhibits procoagulant activity of human islet cells

“…The purity of these duct cell preparations was routinely above 90-95% [2]. The islet cell preparations were cultured for 13±4 days as described previously [2,6]. The cellular composition of the preparations used in the present experiments was comparable with that of human islet cell grafts used in the transplantation trial, with 15-58% insulin-positive cells and 16-66% cytokeratin 19-positive duct cells.…”

“…Cell preparations Human primary duct or islet cell preparations were isolated from 14 human donor organs (age of donors 38±18 years; eight male and six female) and cultured as described previously [2,6]. The organs were procured by European hospitals affiliated with the Eurotransplant Foundation (Leiden, the Netherlands) and processed by the Beta Cell Bank in Brussels within the framework of a multicentre programme on beta cell transplantation in diabetes undertaken by the Juvenile Diabetes Research Foundation Center for Beta Cell Therapy in Diabetes.…”

“…The exocrine fraction was cultured in serum-free medium for at least 4 days, leading to a preparation enriched in duct cells. The purity of these duct cell preparations was routinely above 90-95% [2]. The islet cell preparations were cultured for 13±4 days as described previously [2,6].…”

“…Tubing loop model A whole-blood experiment protocol was adapted from a model described previously [1,2]. Loops made of polyvinyl chloride tubing (inner diameter 6.3 mm, length 390 mm) and treated to give a Corline heparin surface were purchased from Corline (Uppsala, Sweden).…”

“…The expression of tissue factor by beta cells and by contaminating duct cells has been shown to trigger coagulation events [1,2]. Pharmacological inhibition of tissue factor activity exerted by human islet cells is therefore expected to improve beta cell survival following transplantation.…”